(0) Obligation:

Clauses:

select(X1, [], X2) :- ','(!, failure(a)).
select(X, Y, Zs) :- ','(head(Y, X), tail(Y, Zs)).
select(X, Y, .(H, Zs)) :- ','(head(Y, H), ','(tail(Y, T), select(X, T, Zs))).
head([], X3).
head(.(H, X4), H).
tail([], []).
tail(.(X5, T), T).
failure(b).

Query: select(g,g,a)

(1) PrologToDTProblemTransformerProof (SOUND transformation)

Built DT problem from termination graph DT10.

(2) Obligation:

Triples:

selectA(X1, .(X2, X3), .(X2, X4)) :- selectA(X1, X3, X4).

Clauses:

selectcA(X1, .(X1, X2), X2).
selectcA(X1, .(X2, X3), .(X2, X4)) :- selectcA(X1, X3, X4).

Afs:

selectA(x1, x2, x3)  =  selectA(x1, x2)

(3) TriplesToPiDPProof (SOUND transformation)

We use the technique of [DT09]. With regard to the inferred argument filtering the predicates were used in the following modes:
selectA_in: (b,b,f)
Transforming TRIPLES into the following Term Rewriting System:
Pi DP problem:
The TRS P consists of the following rules:

SELECTA_IN_GGA(X1, .(X2, X3), .(X2, X4)) → U1_GGA(X1, X2, X3, X4, selectA_in_gga(X1, X3, X4))
SELECTA_IN_GGA(X1, .(X2, X3), .(X2, X4)) → SELECTA_IN_GGA(X1, X3, X4)

R is empty.
The argument filtering Pi contains the following mapping:
selectA_in_gga(x1, x2, x3)  =  selectA_in_gga(x1, x2)
.(x1, x2)  =  .(x1, x2)
SELECTA_IN_GGA(x1, x2, x3)  =  SELECTA_IN_GGA(x1, x2)
U1_GGA(x1, x2, x3, x4, x5)  =  U1_GGA(x1, x2, x3, x5)

We have to consider all (P,R,Pi)-chains

Infinitary Constructor Rewriting Termination of PiDP implies Termination of TRIPLES

(4) Obligation:

Pi DP problem:
The TRS P consists of the following rules:

SELECTA_IN_GGA(X1, .(X2, X3), .(X2, X4)) → U1_GGA(X1, X2, X3, X4, selectA_in_gga(X1, X3, X4))
SELECTA_IN_GGA(X1, .(X2, X3), .(X2, X4)) → SELECTA_IN_GGA(X1, X3, X4)

R is empty.
The argument filtering Pi contains the following mapping:
selectA_in_gga(x1, x2, x3)  =  selectA_in_gga(x1, x2)
.(x1, x2)  =  .(x1, x2)
SELECTA_IN_GGA(x1, x2, x3)  =  SELECTA_IN_GGA(x1, x2)
U1_GGA(x1, x2, x3, x4, x5)  =  U1_GGA(x1, x2, x3, x5)

We have to consider all (P,R,Pi)-chains

(5) DependencyGraphProof (EQUIVALENT transformation)

The approximation of the Dependency Graph [LOPSTR] contains 1 SCC with 1 less node.

(6) Obligation:

Pi DP problem:
The TRS P consists of the following rules:

SELECTA_IN_GGA(X1, .(X2, X3), .(X2, X4)) → SELECTA_IN_GGA(X1, X3, X4)

R is empty.
The argument filtering Pi contains the following mapping:
.(x1, x2)  =  .(x1, x2)
SELECTA_IN_GGA(x1, x2, x3)  =  SELECTA_IN_GGA(x1, x2)

We have to consider all (P,R,Pi)-chains

(7) PiDPToQDPProof (SOUND transformation)

Transforming (infinitary) constructor rewriting Pi-DP problem [LOPSTR] into ordinary QDP problem [LPAR04] by application of Pi.

(8) Obligation:

Q DP problem:
The TRS P consists of the following rules:

SELECTA_IN_GGA(X1, .(X2, X3)) → SELECTA_IN_GGA(X1, X3)

R is empty.
Q is empty.
We have to consider all (P,Q,R)-chains.

(9) QDPSizeChangeProof (EQUIVALENT transformation)

By using the subterm criterion [SUBTERM_CRITERION] together with the size-change analysis [AAECC05] we have proven that there are no infinite chains for this DP problem.

From the DPs we obtained the following set of size-change graphs:

  • SELECTA_IN_GGA(X1, .(X2, X3)) → SELECTA_IN_GGA(X1, X3)
    The graph contains the following edges 1 >= 1, 2 > 2

(10) YES